Stereoscopic imaging, a technique whereby multiple imaging devices are used to form a three dimensional image through stereopsis, is becoming increasingly common in many fields. Stereoscopic imaging is particularly useful in robotics, where it is often desirable to gather three-dimensional information about an operating environment of a machine. Stereoscopic imaging simulates the binocular visions of human eyes and applies the principle of stereopsis to achieve depth perception. This technique can be reproduced by artificial imaging devices by viewing a given object of interest using multiple imaging devices from slightly different vantage points. Differences between varying views of the object of interest convey depth information about a position of the object, thereby enabling three-dimensional imaging of the object.
During the shooting of videos or television plays, tracking focal length is a difficult and professional task. Main current focal length tracking devices require experienced focal length tracking operators to adjust focal length of the cameras based on the monitor screens and the shooting site situations in real time.
For certain imaging applications, manual focal length adjustment is cumbersome and may be impractical where the imaging device is operated remotely. Accordingly, it is desirable that a focal length adjustment system be able to automatically adjust the focal length to track a moving object of interest.